Downflow forced draft air heater



Dec. 2, 1947. RUSSELL I 2,431,772

DOWNFLOW FORCED DRAF'T AIR HEATER Filed Dec. 22, 1944 Patented Dec. 2, 1947 UNITED- STAT Es "PATENT? OFFICE 2,431,772 DOWNFLOW' FORCED DRAFTAI-R HEATER Kephart P. Russell, 'Shippensb urg; Pa

Application December .22, 1944; Serial "No: 569; 370 1 Claim. (01. 12c 110)-;

This invention relates to air heaters, and more particularly to those of a down draft type.

It has. for one of its objects to improve generally. heaters of this character so as to secure high efficiency and fuel economy in operation.

An important object is to provide a practical and highly efiicient, down draft, circulatory air heater operating with minimum fuel consumption to be of maximum heating benefit in a room or other space to be heated.

Other particular and important objects and advantages to be attained will appear more fully in the followingdet'ailed description of an apparatus embodying'a practical adaptation of the invention.

An illustrative but non-limiting embodiment of the'invention is disclosedin the accompanying drawings, in which:

Figure l is a view partly inside elevation'and partly in vertical section of a complete assembly of apparatus in accordance with the invention;

FigureZ is a horizontal section taken on line 2-'-2 of Figure 1;

Figure-3 is a detailed sectional view, and onan enlarged scale, illustratinga practical form and arrangement of fuel burner; and

Figure 4 is a fragmentary viewillustrating a modified arrangement of air blower fan and associated parts.

Referring now to the drawings-in detail; the numeral 5 designates the base portion of an air heating unit which is mounted on the floor 6. Mounted on-the base 5 is a vertical, generally cylindrical, hollow shell 1 constituting a combined combustion and air heating chamber. This upright cylinder] is closed at its upper end by a conical cover ortop element 1' and the combined-- combustion and heating chamber thus provided tion is connectedbya transverse pipe 9 to an upright exhaust pipe Ill whose upper end portion l I is connected communicably in any conventional manner, to a regular flue or other take-off for the products of combustion; (not shown). shown, the lower end portion l2 ofthe upright exhaust or vent, pipe in is openand terminates a'd-a jacent the floor-6. Bythustermin-ating' the open lower end portion I-Zof' the upright vent pipe ill closet'o but spaced a short distance from the floor 6, the coldairin theimmediate region of the floor is 'draWn'into-the pipe H] by the up-draft created in saidp'ipe by the heated products of combustion from the} exhaust port 8 passing through the lat-' the outer shell 13 is provided afrusto-conical par-' tition l4,- thus providingan annular dead air space The top adjacent the base -5 of the heater. portion of the-outer shell 13 extends some distance above-the conical top or closure member 1' of the shell -1-, and this'extended upper portion ofthe outer shell l3'is closed'by an end wall I6 except for an axial opening I! for the attachment of an air conducting pipe to 'be presently described'more'fullyin detail; Placed within the upper portion of the outer shell I 3 and surrounding'the conical cap or cover 1' 'of the inner shell 7 in annularly spaced relation thereto is a frustoconical partition l8, which latter, as provided and arranged, forms an annular dead air space 19; This dead air space is provided especially as an insulating medium for the top of the heater and to provide for more effective insulation the irustoconical partition I8 is covered throughout the extent thereof witha lining'of conventional insulating material Zllof any suitable character.

, An air conducting pipe or conduit 2!, located externally of the outer'shell [3 of the heater, has

its upper end portion fitted communicably in the opening I? in the top of the outer shell I3 and:

concentric with-the apex of the top .or closure member I of the inner shell I. This pipe or conduit2l,assholw.n, extends vertically and parallel with the outer shell'l3 and its lower end is attached to a conventional blower 22 having any ordinary .fan like; rotor 23. In practice, this blower 22 may be; andspreferably is, located below the floor 6, as indicated in Figure 1, or the same maybe" located: above the floor, as shown- Theblo-wer 22 may' be driven by any suitablepower element, such as for example, an electric motor 21 indicated conventionally in Figure 2. Thus, by operation of the heater, the colder air in the room or space being heated and adjacent the floor 6 is drawn into the tube or duct 25 and forced upwardly through the conduit pipe 2| and thence downwardly through the outer shell l3 and about the inner heated shell I whence the traveling air which has thus become heated is discharged to the outside through a single or plurality of openings 28 provided in the lower portion of the outer shell l3..adjacent the conical inner partition M. The partition l3 thus serves to deflect the heated air downwardly and radially outward through the outlet opening or openings 28 as provided. There may be any suitable number of these openings 28. In the illustration in Figure 2, there are two of these openings 28 disposed diametrically opposite each other.

Through one of the openings 28 (see Figs. 1 and 2) a pipe 29 is projected from the air conduit pipe 2| into the shell I3, thence through aligned openings in the adjacent portions of the conical partition and wall of the inner shell I. From the pipe 2! the pipe 29 extends first upwardly, as at 33, then downward angularly, as at 3|, and thence horizontally, as at 32, across the lower portion of the inner shell I constituting the combustion chamber of the heater. The upper part of this horizontal portion 32 of the pipe 29 is provided with a multiplicity of apertures 33 extending lengthwise thereof, and the free end portion of this horizontal part of the pipe 29 is formed with a receptacle 34 to be used as a priming cup, as will be presently described in detail. By the provision and arrangement of this pipe 29 which is of comparatively restricted size with respect to the size of the conduit pipe 2|, a correspondingly restricted amount of air from the pipe 2| is forced through the pipe 29 in the operation of the heater.

The perforated part of the pipe 23 constitutes a fuel burner in the operation of which a measured quantity of fuel oil is supplied to the pipe 29 along with the air coming from the conduit pipe 2|. I

As shown in Figure 1, a fuel oil supp-1y tank 35 is mounted on a bracket or shelf 33 projected from the side of the outer casing l3. From the bottom of this supply tank 35 is a pipe 3'1 which leads into the hipped portion of the pipe 29 (see Fig. 3) with the end of the pipe discharging downwardly and forwardly toward the bottom of the inclined portion 3| of the pipe 29. This pipe 31, which is of small capacity, is provided with a regulating and metering valve 39 (see Fig. 1) to be regulated and controlled so as to feed only a measured amount of oil, such for example, as drop by drop, from the end portion 38 of the pipe onto the bottom of the portion 3! of the burner pipe 29 as shown more clearly in Figure 3. Thus, if the pipe 29 is properly heated, the drops or otherwise measured quantity of fuel oil discharged upon the portion 31 of the burner pipe 29 is flashed into vaporous form and commingles with the air coming from the conduit pipe 2|, whence the mixture is ignited as it is brought to the apertures 33 in the horizontal portion 32 of the burner pipe 29. For priming purposes, at the beginning of operation of the burner, a quantity of the oil from the pipe 31 is allowed to run into the priming cup or receptacle 34 and there ignited. After the burner pipe 29 has become heated through this priming operation, the fuel oil in the pipe 29 is vaporized, as above By the foregoing, it is apparent that an exceedingly simple yet practical and highly efficient heating apparatus is provided wherein the heated air is discharged and distributed throughout the room in the region of the floor and thus by its natural tendency to rise there is effected a thorough and economical heating of the room or space with a minimum of fuel consumption.

In most installations of the apparatus of the present invention the air blower will be located below the floor 6, substantially as indicated at Figure 1. However, in some installations, where it is not convenient or practical to put the blower below the floor, the same may be located above the floor as indicated in Figure 4, or elsewhere, as may be the more convenient or desirable.

The illustrated construction and arrangement is but one practical adaptation of the invention, and the same admits of considerable modification within the spirit and scope of the invention as defined by the appended claim. The invention, therefore, is not limited to the specific construction and arrangement shown.

Having thus described the invention, what is claimed is:

A forced down draft air circulatory heater, as described, the same comprising a vertical, elongated, hollow, inner, heater shell, closed throughout the entire extent thereof except for an exhaust vent opening in the side thereof between its top and bottom, said inner shell having a conical top end closure, an outer shell surrounding said inner shell in spaced annular relation thereto, said outer shell including a top end wall and a cylindrical side Wall, an outwardly and downwardly extending, annular, frusto-conical partition between said inner and outer shells above and adjacent the bottoms of said inner and outer shells, said annular partition extending entirely from the inner shell to the outer shell and providing an annular dead air space above the bottoms of said inner and outer shells, the outer shell having at least one outlet opening in the wall thereof adjacently above said annular partition between the inner and outer shells, the upper portion of the outer shell being extended above the inner shell and provided with an axial opening, an outwardly and downwardly extending, annular, frusto-conical partition in the upper portion of said outer shell, said partition surrounding the axial opening in the shell and also being spaced concentrically about the conical end portion of said inner shell, said last-named frusto-conical partition extending entirely from the top end wall to the cylindrical side wall of the outer shell and in conjunction with the adjoining side and end wall portions of the outer shell providing an annular dead air space, a fuel burner in the lower portion of said inner shell, and a conduit pipe connected to the axial opening in the upper end of the outer shell for forcing air downwardly under 5 pressure through the annular space between the Number inner and outer shells. 1,175,069 KEPHART P. RUSSELL. 1,583,238 1,757,898 REFERENCES CITED 5 2,047,121 The following references are of record in the 2166834 file of this patent:

UNITED STATES PATENTS Number Number Name Date 10 304,446 526,475 Woodrufi Sept. 24, 1894 726,200

Name Date Mackey et a1. Mar. 14, 1916 Scudder May 4, 1926 Bushman May 6, 1930 Winterfeldt July 7, 1936 Wiltshire July 18, 1939 FOREIGN PATENTS Country Date Great Britain Dec. 30, 1927 France Feb. 29, 1932 

